Manufacture of carbureted water gas



1937- A. JOHNSON El AL I ,240

I I MANUFACTURE OF CARBURETED WATER GAS Filed Nov. 22 1934 on. v

' J0 I INVENTORS ALFRED. dOHhLSON HARLES a ammmsua BY ATTORNEY Patented Aug. 24, 1937 UNITED STATES PATENT OFFICE v r 2,991,240 g MANUFACTURE OF CARBURETED WATER GAS Alfred Johnson, Summit, andCliarles E. Hemminger, Westfield, N. J., assignors to Combustion Utilities Corporation, New York, N. Y., a corporation of Maine Application November 22, 1934, Serial N 0. 754,222

' 11 Claims.

This invention relates to the manufacture of carbureted water gas, and more particularly relates to improvements in process and apparatus for producing gas having a flexible range of heat- 5 ing value and specific gravity adapted for industrial and domestic heating purposes.

A particular object of the present invention is to provide a practical method for employing heavy oils such as bunker C fuel oil as the carbureting medium in the manufacture of carbureted water blown over from the generator during the up- 10 gas. 1 blast and insures ignition and complete combus- Attempts heretofore made to employ heavy fuel tion of the blow gases. by reason of surface comoils of about 12 A. P. I. specific gravity for carbustion effects. The screen affords a high tem- .bureting water gas, have been generally unsucperature surface of extensive area available for 15 cessful. Heavy fuel oils cannot be successfully cracking heavy oil projected directly thereon dur- 15 used as are lighter oils, by spraying the oil onto ing a part of the make cycle, and its construction the checker brick filling of the carbureter of a is such as to withstand the disintegrating effect standard water gas set, because a-large amount of simultaneous high temperatures and cold oil of the carbon black which results from cracking spray much morev readily than the ordinary such oils is carried by the make and blast gases checker-brick filling of the super-heater and car- 20 respectively into the wash box or out the stack, bureter of the standard set. with resultant formation of low grade high car- With the above and other objects and features bon tars and production of dense sooty smoke in view, the invention consists in the improved from the stack. Such oils cannot be successprocess and apparatus for making carbureted fully or economically vaporized and cracked by Water gas which is hereinafter described and 25 spraying them directly upon the generator fuel more particularly defined in the accompanying bed during the ordinary water gas make cycle, claims. I because the same difiiculties with smoke and tar in the drawing forming a part hereof, a pre result as outlined. above, and in addition the genferred form of the apparatus is illustrated in erator fuel economy is adversely affected owing which: 30

. to the rapid quenching of the top of the fuel bed ig- 1 is a Somew d a a matic View in Verby th 11, Another object of the present inventical section of a standard hot valve water gas tion is to provide a process adapted for using set which has been modified to include the re heavy fuel oil as a water gas carbureting mefractory screen element of the present invention dium without the dimculties above referred to. in place of the usual carbureter checker brick. 35 Other important objects of the present inven- Fig. 2 is a somewhat diagrammatic view in vertion are: To provide in a process for carbureting tical section of a modified form of back run water water gas with heavy oil, for efficiently separatgas set embodying features of the invention ining carbon produced on cracking the oil from the eluding a refractory screen in the carbureter. make gas and blow gas, before such gases exit Referring to Fig. 1, numeral it designates a gas 40 from the heat regenerator elements of the apgenerator which is connected at its top through paratus; to provide such a process in which the conduit i2 with a carbureter it. The carbureter potential heat contained in the carbon product is connected at its base throu 6011611111 W with of the oil cracking operation is regenerated and a superheater it. A conduit All, controlled by a used in the process; and to provide improvements hot valve 22, connects the base of generator Ill 46 in standard water gas generating apparatus inat a point below its grate with conduit l2 and eluding particularly an efficient carbon" filtering carbureter it. A hot valve M is mounted in conscreen of uniformly sized small refractory pieces duit it at a point between generator ill and the having an extensive heat transfer surface, to junction of conduit 20 with conduit HE. A secreplace the usual carbureter checker brick. -ond conduit it leads oil from the upper part of 50 The present invention is based in important superheater iii to a wash box 2%, and a gas off part upon the discovery that it is practicable and take line til is ported out from the wash box. The advantageous to employ heavy fuel oil in a. cartop of superheater it has a hinged stack valve 32 bureted water gas process, by substituting a opening into the base of a stack M. screen of uniformly sized small refractory pieces The generator It has therein a grate 36 upon 55 in place of the usual'carbureter checker brick, and by employing a cycle which insures the removal from the gas by the screen of substantially all carbon black produced on cracking the oil, with consequent elimination of blast smoke and tar contamination, and utilization of the potential heat of this thus trapped carbon to improve the heat efliciency of the process. The screen serves also to trap coke dust and oil carbon which there is supported a deep bed of coke or other solid fuel. The carbureter I4 is provided near its base with a refractory checker brick arch 38 upon which is supported a carbon filtering screen 40 composed of small substantially uniformly sized refractory bricks. Screen 40 usual- 13! has a. depth of 1 to 2 feet, the depth varying somewhat depending upon the character of gas which is produced by the plant in operation. Since temperatures as high as 1300 F. to 1800 F. may be developed on the screen 40, it is preferably composed of round or rectangular bricks of "Mullite or similar high alumina refractory adapted to withstand spalling due to the alternate heating and cooling. The individual refractory bricks or pieces which make up the screen are preferably sized so that their thickness lies between inch and 2 inches, and so that if rectangular, their longest dimension does not exceed 3 inches.

Primary air for up-blasting the generator fuel bed enters the base of the generator below the grate through a line 42 controlled by valve 44. The secondary air line 46 connects with conduit I2 adjacent the top of the carbureter, and is controlled by a valve 48. Valved steam lines 50 and 52, located respectively at the base and top of the generator, serve for the introduction of make steam thereto. 'I'he'heavy fuel oil employed for carbureting the make gas is introduced at the top of the generator through a valve-controlled oil spray 54; and oil may be injected into the top of the carbureter through a valved oil supply pipe 56.

As indicated in Fig. l, a gas *offtake conduit 51, controlled by a valve 58, may be installed to conduct gas directly from the base of the generator II! to the top of the superheater I8.

In the modification of the apparatus which is illustrated in Fig. 2 the hot valves are eliminated, as is also the conduit between the base of the generator and the top of the carbureter. Provision is made for admission of reverse blast primary air and of back run steam respectively to the top of superheater [8 through valved air and steam supply lines 59 and 60. A make-gas offtake line 62, controlled by a three-way valve 64 mounted in oiftake conduit 26, establishes controlled communication between the base of generator l0 and the wash box 28. Qther elements of construction are similar to those of Fig. 1.

The preferred operating cycle for the hot valve set illustrated in Fig. 1 is as follows: Assuming that a gas make cycle has just been completed and that the refractory screen 40 contains a substantial quantity of carbon deposited in and on it, the necessary valves are adjusted to admit primary blast air to the base of the generator through air line 42. Secondary air is introduced at the top of the carbureter through line 46. In passing upwardly through the coke fuel bed in the generator, the air reacts with the coke and with any oil residue deposited on and in the coke fuel bed, thus raising the temperature of the fuel bed and producing blow gases which have a carbon monoxide content of 2 to 16 per cent. High blast rates are usually employed so that the blow gases are of relatively low calorific value. On leaving the top of the generator through conduit l2, the blow gases come into intimate contact with an excess volume of secondary air admitted through line 46 and are ignited and burned during their passage downwardly through the carbureter l4. A sufiicient excess of secondary air is admitted to the carbureter to insure complete combustion both of the blow gases and of the oil carbon deposited on the screen 40 during a preceding make cycle. The resultant heat of combustion and sensible heat of the blow gases serves to raise the temperature of the carbureter and screen 40 and of the checker brick filling of superheater IB to a high temperature. From the top of the superheater the blow gases flow through the, stack valve 32 to the stack 34, as in the usual water gas blast cycle. Before commencing the make cycle the secondary air supply is out off by closing valve 48, and stack valve 32 is closed. Introduction of primary air to the base of the generator is continued throughout a brief blow run period during which unburned blow gases pass from the top of the superheater through wash box 28 and main 30 to storage.

After the regular up-blast and blow run cycles have continued for a period sufficient to burn off the carbon previously deposited on screen 40 and to raise the temperature of the fuel bed in generator H] to gas making temperature, the air supply through line 42 is cut off by closing valve 44, and steam is admitted through line 50 to the base of the generator. At the same time carbureting oil, preferably heavy bunker C fuel oil of about 12 A. P. I. gravity, or tar is sprayed upon the top of the incandescent fuel bed in generator ill from oil supply line 54, and rapid vaporization of the oil takes place, together with some cracking. The water gas produced by uptake place in the generator, through conduit l2 into the carbureter and through the refractory screen 40. The high temperature to which the screen 40 has been brought during the preceding blast and blow-run cycles insures thorough cracking and decomposition of the carbureting oil vapors during their passage therethrough. All the carbon and pitchy residue of the oil cracking operation is filtered out of the gas by screen 40 and held thereby ready for combustion during a subsequent air blast cycle. The up-run make gases exit from the apparatus through wash box 28 and are connected thence to storage through main 30. Cracking of oil vapors is largely a surface reaction, and accordingly a considerable proportion of the oil vapors are cracked, with resultant deposition of carbon formed, on the extensive surface of the screen 40. Mullite is a preferred material for the screen because it seems to catalyze, or at least to preferentially promote by surface combustion, the oil cracking reaction. During the up-run cycle just described, the supply of heavy fuel oil to the generator may be supplemented by an additional supply of oil, which may be a lighter gravity oil, introduced directly onto the screen 40 through the oil'spray 56 at the top of the carbureter.

Following completion of the up-run gas making cycle, hot valve 24 is closed, hot valve 22 opened, and the steam supply to the base of the generator is cut off. Steam is now introduced to the top of the generator through line 52, while continuing the supply of oil through spray line 54, and mixture of blue gas and oil gas is passed downwardly through the fuel bed and thence through connection 20 into the carbureter. In passing through the fuel bed the oil vapors are cracked and the carbon is largely trapped in the fuel bed. Any carbon and coke dust which is carried over from the generator by the make gas is filtered out of the gas during passage thereof through screen 40 pipe 56.

Following the down run make cycle, hot valve 5 22 is closed, valve 24 is opened, the supply of oil is cut oil, and steam supply line 54 is closed. Before beginning another up-blast'cycle, the bottom of the generator is purged of combustible gas by a brief up-steam purge run during which the 10 blue gas formed is led off through wash box 28 to storage. -After this purge run the steam supply is cut off, the stack valve 32 is opened, the primary and secondary air supplies turned on, and the blast cycle is repeated. Or the steam purge 15 may be followed by a brief blow-run cycle before the stack valve is opened.

The previously described cycle of operation for the apparatus of Fig. 1 may be varied by passing the mixture of blue gas and oil gas which is produced in the generator during the down runs, directly from the base of the generator to the top I of superheater it through conduit 51. This variation of cycle is effected by opening valve 58 and closing valve 22. Simultaneously with this cycle 25 carbureting oil may be sprayed into the carbureter through pipe 56, and the oil gas thereby produced is conducted through the superheater checker brick and mixed with the down run make gas in the top of the superheater, from which the enriched make gas is conducted to the wash box 28.

Following this modified down make cycle, and before beginning another upblast cycle, the generator may be purged either by a short steam purge,

or by an air purge in which the stack valve 32 is 55 opened, air is introduced simultaneously to the top of the generator through an air inlet 59 and at-the top of the carburetor through pipe 46, and with valves 22 and 24 closed the blow gases produced in the generator are passed .directly to the top of the superheater where they mix with products of combustion resulting from simultaneous passage of air through the carburetor and superheater. g

In the preferred practice of the inventlon em.- 45 ploying the modified apparatus of Fig. 2, the series of cycles is similar to that described above ex cept that a back-run cycle is used in place of the down-run employed in the apparatus of Fig. l, and a reverse air purge is used in operating the 50 apparatus of Fig. 2. Thus the cycle of operation for the apparatus of Fig. 2 includes in series the up-blast, blow run and Lip-run make cycles previously described in connection with Fig. 1. After completing the up run, the baclr. run valve tit is 55 turned to out off communication between the top of the superheater and the wash box, and to cornmunicably connect the wash box with the base of the generator through conduit bit. The steam supply to the base of the generator is discontinued 60 and steam line hit at the top of the superheater is opened. This institutes. a back run of steam through the superheater and carbureter where the steam becomes highly superheated and partially decomposed by contact with the screen til 65 and carbon deposited thereon. After entering the generator ill the back run steam and water gas contacts oil introduced through the spray line "it, and in passing through the generator fuel bed the oil is cracked and a reform gas results which 70 is conducted through conduit 62 to the wash box and thence to storage. In place of steam, natural gas, or a mixture of natural gas and steam, may be introduced to the superheater through pipe ti during the back run. The gas is reformed, or 7 partially reformed, in passing through the carbureter and screen 40, and reformingis completed in the generator fuel bed. At the conclusion of this back run cycle the oil and steam supplies are cut of! and the apparatus is purged by a reverse air blow--the air being admitted through line 59 to the top of'the superheater, and the blow gases leaving the base of the fuel bed and flowing through conduit 82 to the wash box and thence to storage. This reverse blow serves to burn off part of the carbon deposited on screen 40 during the up-run cycle, and to return heat thus produced to the top of the generator fuel bed, as well as to raise the temperature of the carbureter screen 40 to a point where it is effective for igniting and burning the lean blow gases produced on the succeeding up-blast cycle. The reverse blow also leaves the carbureter and superheater filled with air at the beginning of the up-blast cycle, thus insuring complete combustion of the blow gases, inhibiting smoke exhaust from the stack, and placing the apparatus in condition where the secondary air can be turned into the carbureter at the beginning of the up-blast cycle.

A particular feature of the invention. resides in the novel redesign of the standard carbureter unit. This involves complete removal of the carbureter checker brick and substituting therefor the loosely packed body or screen 40 of small refractory pieces supported in the lower portion ple surface for promoting cracking and water gas reactions and for heat exchange and heat storage. The aluminum oxide which is a component of the preferred refractory for the screen is a good promoter for catalytic dehydrogenation, and accordingly the screen may advantageously be used as a carrier for catalysts of the group consisting of nickel, cobalt, iron, copper oxide or sodium sulphide, to insure emcient functioning of the screen in catalyzing hydrocarbon cracking and water gas reactions. Owing to the loose and random packing of the refractory pieces which make up the screen, it can he readily and quickly removed from the carbureter and replaced. The large unobstructed chamber ti winch is provided in the thus redesigned carbureter above the screen iii serves as a combustion chamber for the blow gases and as an oil atomizlng chamber in which carbureting oil introduced through pipe is thoroughly atomized and mixed with the uprun make gas or with the back run steam before coming in contact respectively with the screen at or with the generator fuel bed.

it will be understood that the preferred operating cycles hereinbefore discussed may be varied as desired to meet varying conditions. For example it may be found advantageous to employ a down run or back run of steam during the first part of the make cycle, followed by an up run; or to generate oil gas alone in the generator during a part of the make cycle, without simultaneous use of steam for the purpose of generating water gas.

Carbon deposition upon and within the screen it appears to be greatest with successive reverse blast and up-blast cycles, the screen being more uniformly heated throughout to high temperatures and thereby rendered effective for cracking the heavy oil vapors and screening out of the gas 5 the carbon residues of cracking.

While in the foregoing descriptions of operating cycles coke has been referred to as constituting the generator fuel, one of the principal advantages of the present invention is that soft coal may be used as the generator fuel, whereas it has not been possible heretofore to use soft coal fuel when using bunker C oil as the carbureting medium. When using soft coal as generator fuel,

it is preferred to inject about half of the totalamount of carbureting oil directly into the carbureter through spray pipe 56, rather than spraying all of the oil onto the generator fuel bed.

The process has great flexibility and a very high gas generating capacity. The heating value of the oil-gas-water-gas-blow-gas mixture produced may be adjusted from below 300 B. t. u. per cubic foot to 1200 B. t. u. or more per cubic foot. The specific gravity of the gas may also be varied by varying the character of oil and the extent of oil cracking. The process is extremely economical in its fuel requirements, particularly since the heavy bunker C fuel oil is available at a low price and is an ideal fuel for the reason that it decomposes or cracks down much more readily than gas oil into a large volume of gas having a higher hydrogen content and lower heating value. Another advantage of the present process is that by regenerating the potential heat of the carbon residue of the cracking operation and utilizing such heat in the process, it is possible to gasify as much as or more of the total oil during the down make cycle when a reformed from cracking such oil, is made to serve as the' primary fuel source, largely replacing more expensive coke. In such an operation clinker difficulties are decreased, since the carbon residue of the oil which is deposited on the generator fuel bed is substantially ash free. By operation in accordance with the process of the present invention, a high grade of low carbon tar is produced, and all difficulties with smoky exhaust 60 from the blast stack are eliminated.

Having thus described our invention, what is claimed as new is:

1. In a cyclic process for making combustible gas wherein during an air blast period a bed of solid carbonaceous fuel in a gas generator is raised to incandescence by air blasting, and the potential heat of blow gas thus produced is regenerated by combustion thereof in an adjacent regenerator filled with checkerbrick, and wherein during a gas making period hydrocarbons are cracked by contacting the same with the incandescent fuel bed whereby a hydrocarbon gas is produced together with residual carbon, the steps of passing the said hydrocarbon gas through a carbon filtering ceramic screen of small high alumina brick uniformly sized within minimum and maximum linear dimensions of %"-3" and randomly and loosely packed to a depth of. one to two feet, to separate therefrom all carbon 7 impurities entrained in the gas and thence into and through the regenerator, and during the air blast periods passing the blow gas together with an excess of air through the said ceramic screen and thence into the regenerator to insure combustion of the blow gas and deposited carbon and recovery of the potential heat thereof for use in the process.

2. A process of manufacturing carbureted water gas as carried out in apparatus including a generator containing an ignited solid fuel bed, a carbureter containing a carbon filtering screen of small, ceramic pieces uniformly sized within minimum and maximum linear dimensions of to 3" and randomly and loosely packed to a depth of one to two feet, a superheater filled with checkerbrick and a wash box, which com-- prises the following steps; air blasting the generator fuel bed and storing the resultant heat of the blow gases and of any carbon previously deposited on the screen in the carbureter and superheater by combustion thereof with secondary air, air blasting the fuel bed and passing the resulting blow gases through the carbureter and superheater into the wash box, passing steam upwardly through the fuel bed while simultaneously spraying heavy fuel oil into the top of the fuel bed, and passing the resulting gases through the carbureter screen and superheater into the wash box; passing steam in a reverse direction through the superheater and carbureter screen into the generator and downwardly through the fuel bed while simultaneously contacting the heavy oil with the fuel bed and conducting the resulting gases directly to the wash box; and purging the apparatus by passing air successively through the superheater, carbureter screen and fuel bed and conducting the resulting blow gases directly to the wash box.

3. The improvement in a cyclic process of making mixed oil gas and water gas which, when carried out in an apparatus comprising a single gas generator having a bed of solid fuel, a single carbureter having a large unobstructed combustion and oil atomizing chamber in its upper portion and having in its lower portion an oil cracking and carbon filtering screen about one to two feet in depth comprising a loosely packed body of small ceramic pieces uniformly sized within minimum and maximum linear dimensions of %"-3" supported transversely of the carbureter, said screen having a contact surface at least three times that of the same depth of checkerbrick, and a single superheater filled with checkerbrick, which apparatus has been heated to oil cracking temperatures in a previous air blasting operation, comprises passing steam through the incandescent bed of solid carbonaceous fuel in the generator during the gas-making period whereby water gas is produced, intimately contacting atomized oil with the resulting water gas in the combustion and atomizing chamber of the carbureter, passing the said mixture of water gas and atomized oil through the carbon filtering screen whereby the oil is cracked and gas and carbon black are produced, which carbon black is separated from the gas during its passage through the screen, and during the air blast periods passing air through the said screen to burn off deposited carbon, and regenerating the potential heat thereof for use in the process.

4. The process of manufacturing carbureted water gas as carried out in apparatus including a generator containing an ignited solid fuel bed, a carbureter having a large unobstructed combustion chamber in its upper portion together with a carbon filtering screen of randomly packed small ceramic pieces uniformly sized within minimum and maximum linear dimensions of %"-3" and positioned transversely in the lower portion of the carbureter, a superheater filled with checkerbrick, and a wash box, which process comprises the following steps: air blasting the generator fuel bed and insuring combustion of the resulting blow gases and regeneration of their 5 heat by passing the same together with secondary air through the carbureter combustion chamber and screen and thence into the superheater; passing steam upwardly through the fuel bed whereby water gas is produced, and conducting 10 the gas in series through the carburetor combustion chamber and screen, while atomizing carbureting oil into the water gas, and conducting the resulting carbureted water gas through the screen and superheater into the 15 wash box; passing steam in a reverse direction through the superheater and carbureter screen into the generator whereby water gas is proiiuced by reaction of the steam with the deposited carbon on the screen, atomizing oil into the wa- 20 ter gas entering the generator, passing the mixed water gas and oil downwardly through the fuel bed, and conducting the resulting carbureted water gas directly to the wash box; and purging the apparatus by passing air successively through 2 the superheater, carburetor and fuel bed and conducting the resulting blow gases. directly to the wash box,

5. A process of manufacturing carbureted water gas as carried out in apparatus including 30 a generator containing an ignited solid fuel bed, a carburetor containing a carbon filtering screen of ceramic pieces uniformly sized within minimum and maximum linear dimensions of %"-3" and randomly and loosely packed to a depth of 35 one to two feet, a superheater filled with checkerbrick and a wash box, which comprises the following steps; air blasting the generator fuel bed and regenerating the resultant heat of blow gases and of any carbon previously deposited on the 40 screen in the carbureter and superheater by combustion thereof with secondary air; passing steam fuel bed, and conducting the resulting mixture of water gas and oil gas directly to the wash box; and passing steam upwardly through the fuel bed, introducing atomized oil into the resulting be water gas and passing the resulting water gasoil mixture through the carbureter screen and superheater into the wash box.

6. A process of manufacturing carbureted water as carried out in apparatus including 55 a generator containing an ignited solid fuel bed, a carburetor containing a carbon filtering screen of ceramic pieces uniformly sized within mini mum and maximum linear dimensions of %,"-3" and randomly packed to a depth of one to two on feet, a superheater filled with ohecirerbrick and a wash box, which comprises the following steps; air blasting the generator iuel bed and storing the resultant heat of the blow gases and any carbon previously deposited on the screen in the g carbureter and superheater by combustion thereof with secondary air, passing steam upwardly through the fuel bed while simultaneously introducing heavy fuel oil into the resulting water gas leaving the top of the fuel bed, and passing 7 the resultant gases through the carburetor screen and superheater into the wash box; passing steam and heavy oil vapors downwardly through the generator fuel bed and conducting the resulting gases directly to the wash box while 7 simultaneously generating oil gas by vaporizing and cracking oil in contact with the screen in the carburetor and enriching the down run make gas with the thus generated oil gas; and purging the apparatus by passing air simultaneously downward through the generator and downwardly and upwardly through the carburetor and superheater and exhaustingthe resulting blow gases to atmosphere after admixture in the top of the superheater.

7. Apparatus adapted for the manufacture of carbureted water gas comprising a gas generator adapted to contain a bed of solid fuel, separate gas offtakes for removing gas from the top of the generator and from the base of the generator, a carburetor and superheater connected in series with each of the gas offtakes, the connection between the generator and the carbureter being ported out in the top of the carburetor. a carbon filtering screen consisting of a bed of small ceramic pieces uniformly sized within minimum and maximum linear dimensions of %--3" and randomly and loosely packed to a depth of one to two feet, said screen being supported within the lower part'of the carburetor, the connection between the carbureter and superheater being ported out in the base of the carbureter below the screen, and independent valve-controlled means for spraying hydrocarbon oil downwardly upon the carbureter screen and on the generator fuel bed.

8. Apparatus adapted for the manufacture of carbureted water gas comprising a gas generator adapted to contain a bed of solid fuel, separate gas offtakes for removing gas from the top of the generator and from the base of the generator, a carbureter and superheater and a wash box communicably connected in series with each other and with the gas oiftake leading off from the top of the generator, the connection between the generator and the carburetor being ported out in the top of the carburetor, a valved conduit directly connecting the Wash box with the gas offtake' leading off from the base of the generator, valved air and steam supply pipes opening respectively into the base of the generator and into the superheater, a carbon filtering screen consisting of a bed -of small ceramic pieces uniformly sized within minimum and maximum linear dimensions of %"-3 and randomly and loosely packed to a depth of about 1 to 2 feet supported within the carburetor on a refractory arch, the connection between the carburetor and super heater being ported out in the base of the carburetelbelow the refractory arch, and independent valve-controlled sprays for introducing hydrocarbon oil upon the carburetor screen upon the generator fuel lead.

9. Apparatus adapted for the manufacture oi? carbureted water gas comprising a gas generator adapted to contain a bed of solid. fuel, separate gas offtakes for removing gas from the top of the generator and from the base of the generator, r carburetor and superheater connected in series with each of the gas ofitakes, the connection between the generator and the carbureter being and ported out in the top of the carbureter, a large unobstructed combustion and oil atomizing chamber in the upper portion of the carburetor, a carbon filtering screen consisting of a bed .of ceramic pieces of small high alumina brick uniformly sized within minimum and maximum linear dimensions of %"-3" and randomly and loosely packed to a depth of one to two feet supported within the lower portion of the carbureter, the connection between the carburetor and the superheater being ported out in the base of the carbureter below the screen, and independentvalve-controlled means for introducing hydrocarbon oil into the top of the carbureter and into the top of thegenerator.

10. Apparatus adapted for the manufacture of carbureted water gas comprising a gas generator adapted to contain a bed of solid fuel, a carbureter, superheater and wash box connected in series with the generator, the connection between the generator and the carbureter being ported out in the top of the carbureter, a large unobstructed combustion and oil atomizing chamber formed in the upper portion of the carbureter, a carbon filtering screen consisting of a bed of ceramic pieces of small high alumina brick uniformly sized within minimum and maximum linear dimensions of %"-3" and randomly and loosely packed to a depth of one to two feet supported within the lower portion of the carbureter on a refractory arch, the connection between the carbureter and superheater being ported out in the base of the carbureter below the refractory arch, and a catalyst deposited on the surfaces of the ceramic pieces making up the screen, said catalyst being selected from the group consisting of nickel, cobalt, iron, copper oxide and sodium sulphide.

11. Apparatus adapted for the manufacture of carbureted water gas comprising a gas generator adapted to contain a bed of solid fuel, separate gas oiftakes for removing gas from the top of the generator and from the base of the generator, a carbureter, superheater and wash box communicably connected in series with each other and with the gas ofitake leading from the top of the generator, the connection between the generator and the carbureter being ported out in the top of the carbureter, a valved conduit directly connecting the top of the superheater with the gas ofitake leading off from the base of the generator, valved air and steam supply pipes opening respectively into the base of the generator and into the superheater, a large unobstructed combustion and oil atomizing chamber occupying the upper portion of the carbureter, a carbon filtering screen comprising a loosely and randomly packed bed of uniformly sized small ceramic pieces having minimum and maximum linear dimensions in the range %"-3", said bed having a depth of about 1 to 2 feet and being supported within the lower portion of the carbureter, the connection between the carbureter and the superheater being ported out in the base carbureter below the screen, and independent valved control sprays for introducing hydrocarbon oil into the top of the generator and into the top of the carbureter.

ALFRED JOHNSON. CHARLES E. HEMMINGER. 

